Of all the world's unusual birds, one of the most fascinating is the beautifully coloured Hooded Pitohui, a songbird endemic to Papua New Guinea. As the world's only scientifically confirmed poisonous bird, its vibrant plumage sends a warning to other animals to stay away – including humans. |
A Dangerous Beauty
A member of the Oriolidae family of avians, the Hooded Pitohui (Pitohui dichrous) has striking orange and black feathers, a solid black head with a crest (which raises when on alert) and deep red eyes. It is medium in stature (growing to about 23cm) but has a powerful beak in relation to its size.
However, while undeniably attractive, the bird's feathers (and skin) are coated with an alkaloid called batrachotoxin, which is one of the most potent poisons on the planet. Batrachotoxin is the same neurotoxin found in the poison dart frogs, which secrete the poison from their skin and are, like the Hooded Pitohui, aposematic (endowed with a vivid colouration as a warning to potential predators).
A Deadly Diet
Batrachotoxin is also found in the Choresine Beetle (from the family Melyridae), which forms part of the staple food source of the Hooded Pitohui. Scientists believe these unusual birds eat the beetles as a chemical defence against lice and other ectoparasties. When the females lay their eggs the poison is transferred from their feathers to the outside of the eggs, which serves as a protection from snakes.
Because the source of the poison is dietary, not all birds have the same amount of toxin in their bodies, so an encounter with one may cause more or less reaction than a brush with another.
How Poisonous is Poisonous?
It wasn't until 1989 that the toxicity of the bird was discovered, when a field researcher called Jack Dumbacher was accidentally scratched as he was untangling a net. He was surprised to discover that when he put his scratched finger in his mouth for relief his lips and tongue immediately went numb.
While there are other birds that use neurotoxins as a defence against predators, the Hooded Pitohui is the only one known to be poisonous to humans. Being scratched by or handling one of the birds causes symptoms of varying degrees (from minor to more serious) that include numbness, dizziness, irritation, sneezing and tingling. Higher quantities of this toxin would cause far more serious effects such as paralysis and even death in humans.
In scientific tests on mice, a small amount of the neurotoxin was enough to cause almost instantaneous death. In times gone past, Papua New Guinea locals did eat the bird, but they would skin it and scour the flesh in charcoal before consuming it, which negated the effects of the poison.
An Effective Defence
Although certainly one of the more unusual birds in the world, its highly effective defence mechanism, which is a very stern deterrent to would-be predators, means the Hooded Pitohui isn't in any danger in terms of conservation, and it's actually one of Papua New Guinea's most widespread avian species.
Marissa Ellis-Snow is a freelance nature writer with a special interest in unusual birds. Marissa chooses the expert-led bird tours organised by Naturetrek, which have brought her unforgettable sightings of a wide range of wildlife in some of the most spectacular regions on Earth.
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